Device for processing and digitizing an energy spectrum of an electromagnetic radiation

Abstract

This device for processing and digitizing an energy spectrum of a radiation, comprises a charge preamplification circuit of the integrating circuit type, suitable for being connected to a semiconductor detector; a lag line energy measurement circuit connected to the output of the preamplification circuit; and a sampler connected to the output of the energy measurement circuit. It further comprises a synchronization circuit a current pulse measurement circuit connected to the output of the preamplification circuit and calculating the difference between the output and a differential of the output of the preamplification circuit; and a discrimination circuit forming a binary signal according to the output of the pulse measurement circuit said logic signal controlling the sampling times of the sampler.

1. A device for processing and digitizing an energy spectrum of a radiation, comprising:
 a charge preamplification circuit of the integrating circuit type, suitable for being connected to a semiconductor detector and delivering a preamplified signal at an output; 
 a lag line energy measurement circuit connected to the output of the preamplification circuit; and 
 a sampler connected to the output of the energy measurement circuit, 
 
     wherein it further comprises a synchronization circuits comprising:
 a current pulse measurement circuit connected to the output of the preamplification circuit and calculating the difference between the output of the preamplification circuit and a differential of the output of the preamplification circuit; and 
 a discrimination circuit forming a binary logic signal according to the output of the pulse measurement circuit, said logic signal controlling the sampling times of the sampler. 
 
   
   
     2. The device as claimed in  claim 1 , wherein the synchronization circuits further comprises a smoothing circuit for eliminating the pulses of the logic signal, having a duration longer than a predefined threshold duration. 
   
   
     3. The device as claimed in  claim 2 , wherein the predefined threshold duration is shorter than or equal to the rise time of the charge preamplification circuit. 
   
   
     4. The device as claimed in  claim 1 , wherein the integration time constant of the preamplification circuit is substantially equal to the differentiation time constant of the pulse measurement circuit. 
   
   
     5. The device as claimed in  claim 1 , wherein the pulse measurement circuit comprises:
 a differentiator stage comprising a high gain amplifier, a capacitance connected to the input of said high gain preamplifier, and a resistance connected between the input and the output of the high gain preamplifier; and 
 a subtractor stage connected to the outputs of the preamplification circuit and the differentiator stage.